Inertia actuated cartridge retaining latches

ABSTRACT

A firearm includes inertial cartridge retaining latches which are actuated to release the fired cartridge case from the launcher responsive to cartridge discharge forces.

United States atet [151 3,680,240

Barret al. [451 Aug. 1, 1972 [54] INERTIA ACTUATED CARTRIDGE 1,796,757 3/ 1931 Little ..42/25 RETAINING LATCHES 3,245,350 4/1966 Kelly ..42/1 F Inventors: Irwin R. Barr, Baltimore; Jack H. Hayrnan, Jr., Harford; Harold A. Wilkening, Baltimore, all of Md.

The United States of America as represented by the Secretary of the Army Filed: Dec. 18, 1970 Appl. No.: 99,559

Assignee:

US. Cl. ..42/1 Q, 42/ I F, 42/25 Int. Cl ..F4lc 27/00, F4lc 27/06, F4lc 15/00 Field of Search ..42/1 F,] O, 25

References Cited UNITED STATES PATENTS 2/1929 Swebilius ..42/25 Primary Examiner-Benjamin A. Borchelt Assistant Examiner-C. T. Jordan Attorney-Harry M. Saragovitz, Edward J. Kelly, Herbert Ber] and Albert E. Arnold, Jr.

[5 7] ABSTRACT A firearm includes inertial cartridge retaining latches which are actuated torelease the tired cartridge case from the launcher responsive to cartridge discharge forces.

5 Claims, 3 Drawing Figures INERTIA ACTUATED CARTRIDGE RETAINING LATCHES BACKGROUND OF THE INVENTION This invention relates to grenade launchers for firing grenade rounds comprising a case from which the grenade is propelled and pertains more particularly to latches for releasably retaining the case to the launcher during discharge of the round.

One particular firearm being developed for military use comprises a rifle with a grenade launcher mounted to the barrel thereof, thereby providing for the troops a firearm having both area and point capabilities. Because it is mounted to the rifle barrel, it is important that the launcher be as light as possible. Also, such a firearm requires a firing mechanism whereby the shooter may fire the rifle at selected rates and types of fire and also by the same trigger fire the launcher. This necessarily requires a complicated firing mechanism.

SUMMARY OF THE INVENTION The present invention serves to lighten the weight of the launcher and simplify the firing mechanism thereof by providing latches, for releasably retaining the grenade round to the launcher during discharge thereof, which are completely self-contained except for springs that bias them to their engaging positions and which are automatically actuated by recoil forces.

This is achieved by providing on each of the latches an inertial mass which opposes the recoil displacement of the launcher by the forces generated by discharge of the round, thereby actuating the latch to its disengaged position for release of the fired case.

Other objects and advantages of the invention will be apparent from the following specification and the accompanying drawing which are for the purpose of illustration only.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a fragmentary top view of the grenade launcher showing in cross-section the latches of this invention mounted therein and disposed in their engaging positions;

FIG. 2 is a view similar to FIG. 1 but showing the latches actuated to their disengaged positions; and

FIG. 3 is a cross-sectioned view taken along line 33 of FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT Shown in the drawing is a launcher 12 for firing a grenade round 14 such as is disclosed in the co-pending patent application by N. .1. La Costa for Grenade Round with Means Giving Forward Momentum to the Fired Case Ser. No. 99,698, filed Jan. 12, 1970 and which includes a case 16 provided with an annular groove 18 therearound adjacent base 20 thereof. Launcher 12 includes a breechblock 22 provided with a front face 24 which is contacted by base 20 when round 14 is loaded to the launcher. A lip 26 extends forwardly from the bottom section of face 24 for engagement by the rim of base 20 to correctly locate round 14 relative to breechblock 22 when loaded to launcher l2. Extending longitudinally through breechblock 22 is a longitudinal bore 28 for slidingly receiving a firing pin 30 and extending laterally through the breechblock 22 above bore 28 is a chamber 32 which is rectangular in vertical cross-section. Chamber 32 accommodates a pair of latches 34 which are pivotally mounted to breechblock 22 on opposite sides thereof by means of pins 36 for displacement between engaging and disengaged positions relative to groove 18. Pins 36 are vertically disposed so as to be normal to the longitudinal direction of the recoil forces RF generated when round 14 is fired.

Each of the latches 34 comprises an arm 38, which extends along the outside of breechblock 22, and an inertial block 40 which extends from the arm into chamber 32. Arm 38 is provided at the end thereof which is forwardly of pin 36 with a hook 42 which is insertable into groove 18 of round 14 when loaded to launcher 12 thereby releasably holding base 20 of such round against front face 24 to assure impact of firing pin 30, when released, against primer 44 in such base. Provided on the inside of the end of arm 38 which is rearwardly of pin 36 is a recessed seat 46 for a spring 48 which acts to resiliently hold the latch in the engaging position thereof.

As shown in FIGS. 1 and 2, one of the inertial blocks 40 is provided with a vertical slot 50 while the other one is provided with a tongue 52 which is received by such slot and which cooperates therewith to assure that both latches 34 pivot in unison between their engaging and disengaged positions. As shown also in FIGS. 1 and 2, each of the inertial blocks 40 has a center of mass which is indicated at CM, and it is noted that the centers of mass CM are located inside and to the rear of pins 36. Thus, when round 14 is fired, the discharge forces are applied to breechblock 22, to cause accelerated recoil displacement thereof, and this recoil displacement is transmitted to latches 34 through pins 36. The accelerated recoil displacement transmitted to latches 34 is opposed by the inertia of inertial blocks 40, and with CM thereof being located inside and to the rear of the pivotal point of the latches at pins 36 the latches are pivoted against the bias of the respective springs 48 to their disengaged positions. Obviously, inertial blocks 40 must have sufficient mass so that their resistance to the accelerated recoil displacement of breechblock 22 will overcome the bias of springs 48 and the resistance of latches 34 to displacement to their disengaged positions.

OPERATION Round 14 is loaded to laucher 12 by resting base 20 of the round on lip 26 and then pressing rearwardly on the round, thereby causing latches 34 to be biased outwardly until hooks 42 thereon snap into groove 18. When round 14 is fired, the recoil displacement of breechblock 22 is opposed by the mass of inertial blocks 40 causing latches 34 to be pivoted to their disengaged positions, freeing fired case 16 for ejection by the forward momentum imparted thereto, as described in the aforementioned co-pending patent application by N. J. La Costa.

We wish it to be understood that we do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

We claim:

1. In a firearm for firing an ammunition round comprising a case with an annular extractor groove, the improvement wherein said firearm includes at least one latch releasably engageable with said extractor groove for securing said round to said firearm for discharge, said latch including an inertial block disposed to oppose the recoil forces generated by discharge of said round and thereby actuate said latch from engagement with said extractor groove.

2. The invention as defined in claim 1 wherein said latch is disposed for pivotal displacement between an engaging and a disengaged position relative to said extractor groove by means of a pin disposed normal to the direction of the recoil forces and through said latch intermediate the front and rear ends thereof.

3. The invention as defined in claim 2 wherein said latch includes a hook located on the front end thereof for engagement with said extractor groove when said latch is in the engaging position, and wherein the center of mass of said inertial block is located inwardly and to the rear of said pin.

4. The invention as defined in claim 3 wherein said firearm includes a pair of said latches pivotally mounted diametrically apart thereto, and including means interlocking said pair of latches to assure simultaneous displacement between the engaging and the disengaged positions thereof.

5. The invention as defined in claim 4 wherein said interlocking means comprise a tongue extending from said inertial block of one of said pair of latches, and a slot disposed in said inertial block of the other one of said pair of latches for receiving said tongue. 

1. In a firearm for firing an ammunition round comprising a case with an annular extractor groove, the improvement wherein said firearm includes at least one latch releasably engageable with said extractor groove for securing said round to said firearm for discharge, said latch including an inertial block disposed to oppose the recoil forces generated by discharge of said round and thereby actuate said latch from engagement with said extractor groove.
 2. The invention as defined in claim 1 wherein said latch is disposed for pivotal displacement between an engaging and a disengaged position relative to said extractor groove by means of a pin disposed normal to the direction of the recoil forces and through said latch intermediate the front and rear ends thereof.
 3. The invention as defined in claim 2 wherein said latch includes a hook located on the front end thereof for engagement with said extractor groove when said latch is in the engaging positiOn, and wherein the center of mass of said inertial block is located inwardly and to the rear of said pin.
 4. The invention as defined in claim 3 wherein said firearm includes a pair of said latches pivotally mounted diametrically apart thereto, and including means interlocking said pair of latches to assure simultaneous displacement between the engaging and the disengaged positions thereof.
 5. The invention as defined in claim 4 wherein said interlocking means comprise a tongue extending from said inertial block of one of said pair of latches, and a slot disposed in said inertial block of the other one of said pair of latches for receiving said tongue. 